With the final declaration of war on September 3, 1939, the blithe world of le beau monde collapsed and many members rallied to the war effort. Lady Mendl and the Duchess of Windsor established a charity known as “Le Colis de Trianon-Versailles,” which sent “soldiers’ boxes” to the frontline trenches of France. As Lady Mendl stated in a letter enlisting support for the charity in America, “As two American-born women, whose lives and interests are so interwoven with those of France, the Duchess of Windsor and myself now turn to our friends at home and ask for their help. We have all enjoyed many hours of happiness in our beloved France so will you now help in some measure to repay the debt we owe?”
Mrs. Ector Munn and Mrs. Harrison Williams, among others, chaired the American branch of Le Colis de Trianon-Versailles. In 1940, with the support of Lady Mendl and the Duchess of Windsor, they organized the exhibition Paris Openings to raise money for the French war charity. Held at the John Wanamaker Auditorium in New York, the exhibition featured evening dresses worn by members of the Windsor set. Each dress was chosen for its “hallowed memory,” a dress that had been worn on some “Great Occasion.” These costumes reveal the supreme and unsurpassed craftsmanship of the couture métier in the five years leading up to World War II. At the same time, they reveal how the Duchess of Windsor and her set conscripted fashion—the very expression of their blithe lives—as a unified display of their support for the war effort.